| 摘要 |
PURPOSE: To prevent the deviation of an optical axis by deflecting a laser beam in the direction orthogonal to the scanning direction of the laser beam and inserting a convex cylindrical lens far compensating the incident position on the optical path just in front of an image sensor. CONSTITUTION: In a confocal optical system 1 converging a laser beam L1 on the surface of an objectωby means of an objective lens 18, making the reflected beam to be received by an image sensor 19 and detecting the distance information to the objectω, a concave and a convex cylindrical lenses 4, 3 are arranged between a beam splitter 14 and the image sensor 19. The convex cylindrical lens 3 is inserted on the optical path just in front of the image sensor 19, deflects the laser beam L1 in the direction orthogonal to the scanning direction Y of the laser beam L1 and compensates the incident position of the laser beam L1 on the image sensor 19. Namely, when the laser beam L1 whose optical axis is vertically deviated is made incident on it, the convex cylindrical lens 3 deflects the laser beam in the direction orthogonal to the scanning direction.
|
